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Polish Archives of Internal Medicine Mar 2024
Topics: Humans; Metanephrine; Pheochromocytoma; Body Fluids; Adrenal Gland Neoplasms
PubMed: 38533849
DOI: 10.20452/pamw.16711 -
Acta Universitatis Carolinae. Medica 1963
Topics: Catecholamines; Chromatography; Electrophoresis; Epinephrine; Humans; Metanephrine; Normetanephrine; Paraganglioma; Phenethylamines; Pheochromocytoma; Sympathomimetics
PubMed: 14163440
DOI: No ID Found -
Annals of Laboratory Medicine Sep 2022To identify candidate external quality assessment (EQA) materials for normetanephrine and metanephrine measurements, we assessed the commutability of eight processed...
BACKGROUND
To identify candidate external quality assessment (EQA) materials for normetanephrine and metanephrine measurements, we assessed the commutability of eight processed human plasma samples. The agreement between routine assays and the candidate reference measurement procedure (cRMP) was also evaluated.
METHODS
Fifty-three clinical samples and eight processed plasma samples were prepared. The processed samples included pooled and individual plasma samples spiked with pure normetanephrine and metanephrine and non-spiked pooled and individual plasma samples. The clinical and processed samples were subjected to four routine isotope dilution tandem mass spectrometry assays and cRMP. Commutability was assessed based on two approaches recommended by the CLSI and International Federation of Clinical Chemistry (IFCC). Passing-Bablok regression and Bland-Altman analysis were used to evaluate the agreement between the routine assays and cRMP.
RESULTS
The commutability results of the CLSI approach were better than those of the IFCC approach. For the CLSI approach, spiked individual plasma samples and spiked high-concentration pooled plasma samples were commutable for all routine assays for both analytes. The non-spiked pooled plasma sample was commutable for two out of four routine assays for metanephrine and three out of four routine assays for normetanephrine. The agreement between the routine assays and the cRMP was satisfactory, except for one routine assay showing significant bias.
CONCLUSIONS
High-concentration spiked pooled plasma samples and spiked individual plasma samples are candidate EQA materials for normetanephrine and metanephrine measurements.
Topics: Hematologic Tests; Humans; Mass Spectrometry; Metanephrine; Normetanephrine
PubMed: 35470275
DOI: 10.3343/alm.2022.42.5.575 -
Archives of Internal Medicine Feb 1977To facilitate the screening for pheochromocytoma, we have validated the use of single-voided, spot urine specimens for the determination of total metanephrines....
To facilitate the screening for pheochromocytoma, we have validated the use of single-voided, spot urine specimens for the determination of total metanephrines. Metanephrine excretion was found to be quite constant throughout the day and night in ten patients with essential hypertension and seven patients with pheochromocytoma. The levels in single-voided specimens were closely correlated to those in 24-hour specimens in 100 hypertensive subjects. The mean +/- 2 SD metanephrine excretion in single-voided urine specimens from 500 hypertensive subjects was 0.351 +/- 0.356 mug/mg of creatinine.
Topics: Adolescent; Adrenal Gland Neoplasms; Adult; Epinephrine; Humans; Hypertension; Metanephrine; Pheochromocytoma
PubMed: 836117
DOI: No ID Found -
Physiological Research 2015This work discusses the clinical performance of deconjugated metanephrine (MN), normetanephrine (NMN) and 3-methoxytyramine (3MT) determined in the basal first morning...
This work discusses the clinical performance of deconjugated metanephrine (MN), normetanephrine (NMN) and 3-methoxytyramine (3MT) determined in the basal first morning urine using a chromatographic method with electrochemical detection for the clinical diagnosis of pheochromocytoma (PHEO) and paraganglioma (PGL). Urine samples were collected from 44 patients (36 with PHEO, 8 with PGL) aged 54+/-17 (20-78) years (22 females, 22 males). A sampling of biological materials was performed preoperatively and about one week, six months and one year after adrenal gland surgery. The control group consisted of 34 PHEO/PGL patients more than 4 months after adrenal gland surgery. All subjects in the control group were without a diagnosis of PHEO or PGL. Clinical sensitivity was 55 % for MN, 64 % for NMN, 80 % for combination of both MN and NMN, and only 23 % for 3TM. Clinical specificity calculated from the control group was 93 % for MN, 95 % for NMN, 95 % for the combination MN and NMN, and 97 % for 3TM. Cut-off values for deconjugated metanephrines in the basal urine were 310 (MN), 690 (NMN) and 250 microg/l (3MT). Chromatographic determination of deconjugated urinary metanephrines, which is simple without the necessity of special laboratory material, can serve for the screening of PHEO or PGL patients. Urine NMN and 3MT exerts an association to malignity, and all markers are associated with tumor mass. However, the principal laboratory diagnosis of PHEO or PGL must be based on plasma-free metanephrines and plasma chromogranin A with better performance in the laboratory diagnosis of PHEO or PGL.
Topics: Adrenal Gland Neoplasms; Adult; Aged; Biomarkers; Chromatography, High Pressure Liquid; Clinical Laboratory Techniques; Dopamine; Female; Humans; Male; Metanephrine; Middle Aged; Normetanephrine; Paraganglioma; Pheochromocytoma; Young Adult
PubMed: 26680494
DOI: 10.33549/physiolres.933109 -
Methods in Molecular Biology (Clifton,... 2016Measuring urinary metanephrines aides in the diagnosis of pheochromocytomas-catecholamine producing tumors. Liquid chromatography-tandem mass spectrometry (LC-MS/MS)...
Measuring urinary metanephrines aides in the diagnosis of pheochromocytomas-catecholamine producing tumors. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) allows for greater sensitivity and simpler sample preparation as compared with other techniques. Here we describe a simple LC-MS/MS method for measuring metanephrines in urine. Each urine sample was treated with diphenylboronic acid to create boronate complexes, and then applied to a Bond-Elut Plexa cartridge. After solid phase extraction, samples were concentrated and analyzed on an Atlantis T3 column with chromatographic run time totaling 8.5 min. MS/MS was set in positive electrospray ionization mode with multiple reaction monitoring for data collection. The assay was linear from 0.2 to 27.4 μmol/L and 0.3 to 14.6 μmol/L for metanephrine and normetanephrine, respectively. Intra-assay and total precision at three concentration levels over 10 days were <5 % for metanephrine and <10 % for normetanephrine.
Topics: Analytic Sample Preparation Methods; Boronic Acids; Chromatography, High Pressure Liquid; Formates; Humans; Metanephrine; Normetanephrine; Solid Phase Extraction; Tandem Mass Spectrometry; Urinalysis
PubMed: 26602127
DOI: 10.1007/978-1-4939-3182-8_17 -
South Dakota Medicine : the Journal of... Jul 2013A commonly received question in the clinical laboratory is as follows: what is the best test for pheochromocytoma? A widely variable presentation and potentially... (Review)
Review
A commonly received question in the clinical laboratory is as follows: what is the best test for pheochromocytoma? A widely variable presentation and potentially catastrophic consequence make this a feared neoplasm despite its infrequent encounter. Because various biochemical testing modalities are available, test selection is often confusing. This selection process can be made easier through a better understanding of catecholamine producing neoplasms. The aim of this article is to provide a review of catecholamine producing neoplasms and give recommendations on appropriate test selection.
Topics: Adrenal Gland Neoplasms; Humans; Magnetic Resonance Imaging; Metanephrine; Pheochromocytoma; Tomography, X-Ray Computed
PubMed: 23957112
DOI: No ID Found -
Clinical Chemistry Dec 2018
Review
Topics: Adrenal Gland Neoplasms; Blood Chemical Analysis; Catecholamines; Humans; Metanephrine; Pheochromocytoma
PubMed: 30201801
DOI: 10.1373/clinchem.2018.290791 -
Clinical Chemistry Dec 2014Pheochromocytomas and paragangliomas (PPGLs) are potentially lethal yet usually surgically curable causes of endocrine hypertension; therefore, once clinical suspicion... (Review)
Review
BACKGROUND
Pheochromocytomas and paragangliomas (PPGLs) are potentially lethal yet usually surgically curable causes of endocrine hypertension; therefore, once clinical suspicion is aroused it is imperative that clinicians choose the most appropriate laboratory tests to identify the tumors.
CONTENT
Compelling evidence now indicates that initial screening for PPGLs should include measurements of plasma free metanephrines or urine fractionated metanephrines. LC-MS/MS offers numerous advantages over other analytical methods and is the method of choice when measurements include methoxytyramine, the O-methylated metabolite of dopamine. The plasma test offers advantages over the urine test, although it is rarely implemented correctly, rendering the urine test preferable for mainstream use. To ensure optimum diagnostic sensitivity for the plasma test, reference intervals must be established for blood samples collected after 30 min of supine rest and after an overnight fast when measurements include methoxytyramine. Similarly collected blood samples during screening, together with use of age-adjusted reference intervals, further minimize false-positive results. Extents and patterns of increases in plasma normetanephrine, metanephrine, and methoxytyramine can additionally help predict size and adrenal vs extraadrenal locations of tumors, as well as presence of metastases and underlying germline mutations of tumor susceptibility genes.
SUMMARY
Carried out correctly at specialist endocrine centers, collection of blood for measurements of plasma normetanephrine, metanephrine, and methoxytyramine not only provides high accuracy for diagnosis of PPGLs, but can also guide clinical decision-making about follow-up imaging strategies, genetic testing, and therapeutic options. At other centers, measurements of urine fractionated metanephrines will identify most PPGLs.
Topics: Adrenal Gland Neoplasms; Clinical Laboratory Techniques; Dopamine; Humans; Metanephrine; Normetanephrine; Paraganglioma; Pheochromocytoma
PubMed: 25332315
DOI: 10.1373/clinchem.2014.224832 -
Clinical Chemistry and Laboratory... Sep 2020
Topics: Blood Specimen Collection; Cannula; Healthy Volunteers; Humans; Metanephrine; Phlebotomy
PubMed: 32286244
DOI: 10.1515/cclm-2020-0326